A cross-point switch (also known as a crossbar switch, a matrix switch, etc.) includes various switches arranged in a matrix configuration with multiple input and output lines that form a crossed pattern of interconnecting lines between which a connection may be established by closing a switch located at each intersection, the elements of the matrix. There are applications in networks for high-data-rate cross-point switches, such as to replace optical switches where electronic switches can provide better performance and cost especially when coupled with photonic integration and to augment packet layer switching such as in data centers where cross-point switches can provide superior power performance over packet switches, especially for large data flows that do not need packet layer switching, i.e., large flows between adjacent switches. In these applications, the high-data-rate cross-point switches provide switching of connections at data rates of 10 Gb/s and above, i.e., flow switching of entire wavelengths of traffic. Example applications of the high-data-rate cross-point switches for networking applications are described in commonly-assigned U.S. Pat. No. 9,124,383, “HIGH CAPACITY FIBER-OPTIC INTEGRATED TRANSMISSION AND SWITCHING SYSTEMS,” and commonly-assigned U.S. patent application Ser. No. 14/924,802, “HIGH PORT COUNT SWITCHING MODULE, APPARATUS, AND METHOD,” the contents of which are incorporated by reference.
There are existing cross-point switches which address high-data-rate signals. Generally, conventional cross-point switches are implemented as active switches using a mux/selector architecture in a silicon-germanium (SiGe) process to accommodate the fast data rate. Importantly, conventional cross-point switches focus on preserving signal quality within the matrix configuration using complex and power inefficient circuitry such as linear amplifiers, differential lines, line termination elements, and the like. Specifically, conventional cross-point switches have a power consumption of several Watts or more. Other approaches have considered simple Complementary metal-oxide semiconductor (CMOS)-based designs such as in U.S. Pat. No. 6,356,111, but these approaches only suggest a single N-type metal-oxide-semiconductor (NMOS) switching element which will not work for high-data-rate signals (i.e., 10 Gb/s and above) due to excessive cross-talk and insufficient transmission of high bits (“1's”). Yet other approaches have shown analog-type cross-point switches, but these are not optimized for digital Non-Return to Zero (NRZ) signal transmission and use NMOS only devices as switching elements along with full termination of transmission lines. This approach is appropriate for analog signal transmission as it preserves signal quality, but it is extremely excessive for digital NRZ signals from power, cost, and complexity perspective.
In terms of a cross-point switch for switching digital signals, it is necessary to minimize power consumption, cost, and complexity such that the cross-point switch can be an effective replacement for optical switches as well as effectively augment packet switches in a layered approach.